RU2791938C1 - Transmission of interlayer prediction in video bit stream - Google Patents

Abstract

FIELD: video encoding/decoding.

SUBSTANCE: invention relates to video encoding and decoding, more specifically to transmission of an interlayer prediction in a video bit stream. A method and a device are proposed, containing a computer code configured to induce a processor or processors to perform parsing of at least one set of video parameters, containing at least one syntaxis element indicating whether at least one layer in a scaled bit stream is one of a dependent layer of the scaled bit stream and an independent layer of the scaled bit stream. A number of dependent layers of the scaled bit stream, including a dependent layer, is determined based on a set of flags included in VPS. An image on the dependent layer is decoded by parsing and interpretation of a list of interlayer reference images, and, on the independent layer, without parsing and interpretation of the list of interlayer reference images.

EFFECT: increase in the efficiency of video encoding/decoding.

20 cl, 14 dwg, 1 tbl

Description

CROSS-REFERENCE TO RELATED APPLICATION

[1] This application claims priority of U.S. Provisional Application No. 62/903,652, filed September 20, 2019, and U.S. Patent Application No. 17/019,713, filed September 14, 2020, which are incorporated herein in their entirety.

BACKGROUND OF THE INVENTION

1. Technical field to which the invention belongs

[2] The disclosed subject matter of the invention relates to video encoding and decoding, and more specifically, to the transmission of interlayer prediction in a video bitstream.

2. Description of the prior art

[3] Video encoding and decoding using motion-compensated inter-picture prediction has been known for decades. Uncompressed digital video may consist of a series of images, each image having a spatial size of, for example, 1920×1080 luma samples and associated chrominance samples. A series of images can have a fixed or variable image rate (informally also known as frame rate), such as 60 images per second or 60 Hz. Uncompressed video has significant bitrate requirements. For example, 1080p60 4:2:0 video at 8 bits per sample (1920x1080 brightness sample resolution at 60Hz frame rate) requires bandwidth close to 1.5Gbps. An hour of such video requires more than 600 GB of disk space.

[4] One of the goals of video encoding and decoding may be to reduce the redundancy of the input video signal through compression. Compression can help reduce the aforementioned bandwidth or storage requirements, in some cases by two orders of magnitude or more. Both lossless and lossy compression, as well as a combination of both, can be used. Lossless compression refers to techniques where an exact copy of the original signal can be reconstructed from the compressed original signal. When lossy compression is used, the reconstructed signal may not be identical to the original signal, but the distortion between the original and reconstructed signals is small enough to make the reconstructed signal useful for the intended application. In the case of video, lossy compression is widely used. The amount of distortion allowed depends on the application; for example, users of certain consumer streaming applications may tolerate higher distortion than users of television distribution applications. The achievable compression ratio may reflect the following: higher distortion resolution/tolerance may result in a higher compression ratio.

[5] The video encoder and video decoder may use techniques from several broad categories including, for example, motion compensation, transformation, quantization, and entropy coding, some of which will be presented below.

[6] Historically, video encoders and video decoders tended to work with a given picture size, which in most cases was defined and held constant for a coded video sequence (CVS), group of pictures (GOP), or similar multi-picture time frame. For example, in MPEG-2, the system design is known to change the horizontal resolution (and hence the image size) depending on factors such as scene activity, but only for I-pictures, hence typically for GOP. The resampling of reference pictures to use different resolutions in CVS is known, for example, from ITU-T Rec. H.263, Annex P. However, here the image size is not changed, only the reference pictures are resampled, with the result that only parts of the image canvas can potentially be used (in in the case of downsampling) or only part of the captured scene (in the case of upsampling). In addition, H.263 Annex Q allows resampling of an individual macroblock by a factor of two (in each dimension), up or down. Again, the image size remains the same. The macroblock size is fixed in H.263 and therefore does not need to be transmitted.

[7] Image resizing in predicted images has become more common in modern video coding. For example, VP9 allows you to perform reference picture resampling (RPR) and resampling the entire picture. Likewise, some of the proposals made in relation to VVC (including, for example, Hendry, et. al., "On adaptive resolution change (ARC) for VVC", JVT document JVET-M0135-v1, January 9-19, 2019, incorporated herein in its entirety) allow resampling of entire reference pictures with a different, higher or lower resolution. This document proposes to encode different resolution candidates in a sequence parameter set and refer to them using the syntax elements for each image in the image parameter set.

DISCLOSURE OF THE INVENTION

[8] In order to address one or more of the various technical issues, this disclosure describes new syntaxes and their uses for conveying scaling in a video bitstream. Thus, improved (de)coding efficiency can be achieved.

[9] According to the present embodiments, with Reference Picture Resampling (RPR) or Adaptive Resolution Resampling (ARC), additional overhead to support scalability can be achieved by modifying High Level Syntax (HLS). In technical aspects, interlayer prediction is used in a scalable system to increase the coding efficiency of enhancement layers. In addition to motion compensated spatial and temporal predictions that are available in a single layer codec, interlayer prediction uses resampled video data of a reconstructed reference picture from a reference layer to predict the current enhancement layer. Then, the resampling process for interlayer prediction is performed at the block level by modifying the existing interpolation process for motion compensation. This means that no additional resampling process is required to support scalability. This disclosure describes high level syntax elements for supporting spatial/qualitative scalability using RPR.

[10] Included is a method and apparatus comprising a memory configured to store computer program code and a processor or processors configured to access the computer program code and operate in accordance with instructions from the computer program code. The computer program code includes a parsing code configured to cause at least one processor to parse at least one video parameter set (VPS) containing at least one syntax element indicating whether at least one layer is in bitmap scalable stream by one of a dependent scalable bitstream layer and an independent scalable bitstream layer defining a code configured to cause at least one processor to determine the number of dependent layers, including a dependent layer, of a scalable bitstream based on a plurality of flags included in the VPS, the first decoding code , configured to cause at least one processor to decode an image in a dependent layer by parsing and interpreting an interlayer reference picture list (ILRP), a second decoding code configured to cause at least one processor to decode an image in independent layer without parsing and interpreting the ILRP list.

[11] According to embodiments, the second decoding code is further configured to cause at least one processor to decode an image in an independent layer by parsing and interpreting a reference picture list that does not include any decoded picture of another layer.

[12] According to embodiments, the list of interlayer reference pictures includes a decoded picture of another layer.

[13] According to embodiments, the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether another syntax element specifies the maximum number of layers.

[14] According to embodiments, the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether the VPS contains a flag indicating whether another layer in the scalable bitstream is a reference layer for at least one layer.

[15] According to embodiments, the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether a flag indicates another layer as a reference layer for at least one layer, by setting an index of another layer, and an index of at least one layer, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining if the VPS contains another syntax element indicating a value less than a certain number of dependent layers.

[16] According to embodiments, the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether a flag indicates another layer as not being a reference layer for at least one layer by setting the index of the other layer and an index of at least one layer, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining if the VPS contains another syntax element indicating a value less than a certain number of dependent layers.

[17] According to embodiments, the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether the VPS contains a flag indicating whether to decode a plurality of layers, including at least one layer, by interpreting ILRP list.

[18] According to embodiments, the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether the VPS contains a flag indicating whether a plurality of layers, including at least one layer, needs to be decoded, without interpreting ILRP list.

[19] According to embodiments, the parsing code is further configured to cause at least one processor to parse at least one VPS and further comprises determining whether the VPS contains a flag indicating whether to decode a plurality of layers, including at least one layer, by interpreting the ILRP list.

BRIEF DESCRIPTION OF THE DRAWINGS

[20] Additional features, essence and various advantages of the disclosed subject matter will be more apparent from the following detailed description and the accompanying drawings, which depict the following.

[21] FIG. 1 is a schematic illustration of a simplified block diagram of a communication system in accordance with an embodiment.

[22] FIG. 2 is a schematic illustration of a simplified block diagram of a communication system in accordance with embodiments.

[23] FIG. 3 is a schematic illustration of a simplified block diagram of a decoder in accordance with embodiments.

[24] FIG. 4 is a schematic illustration of a simplified block diagram of an encoder in accordance with embodiments.

[25] FIG. 5A is a schematic illustration of options for transmitting ARC/RPR parameters in accordance with the prior art.

[26] FIG. 5B is a schematic illustration of options for transmitting ARC/RPR parameters in accordance with the prior art.

[27] FIG. 5C is a schematic illustration of options for transmitting ARC/RPR parameters in accordance with embodiments.

[28] FIG. 5D is a schematic illustration of options for transmitting ARC/RPR parameters in accordance with embodiments.

[29] FIG. 5E is a schematic illustration of options for transmitting ARC/RPR parameters in accordance with embodiments.

[30] FIG. 6 is a schematic illustration of image permission transmission in accordance with embodiments.

[31] FIG. 7 is a schematic illustration of image size transmission and matching window in SPS according to embodiments.

[32] FIG. 8 shows a schematic illustration of the transmission of the presence of interlayer prediction in SPS in accordance with embodiments.

[33] FIG. 9 is a schematic illustration of the transmission of an interlayer prediction index in a slice header, in accordance with embodiments.

[34] FIG. 10 is a schematic illustration of a computer system in accordance with embodiments.

IMPLEMENTATION OF THE INVENTION

[35] The proposed features discussed below may be used alone or combined in any order. In addition, embodiments may be implemented by processing circuits (eg, one or more processors or one or more integrated circuits). In one example, one or more processors execute a program that is stored on a non-transitory computer-readable medium.

[36] FIG. 1 illustrates a simplified block diagram of a communication system (100) according to an embodiment of the present disclosure. System (100) may include at least two terminals (110 and 120) interconnected via network (150). For unidirectional data transmission, the first terminal (110) may encode video data at the local location for transmission to another terminal (120) via the network (150). The second terminal (120) may receive the encoded video data of another terminal from the network (150), decode the encoded data, and display the recovered video data. Unidirectional data transfer may be common in media serving applications and the like.

[37] FIG. 1 shows a second pair of terminals (130, 140) providing support for bidirectional encoded video transmission, such as may occur during a video conference. For bi-directional data transmission, each terminal (130, 140) may encode video data captured at a local location for transmission to another terminal over a network (150). Each terminal (130, 140) may also receive the encoded video data transmitted by the other terminal, may decode the encoded data, and may display the recovered video data on a local display device.

[38] FIG. 1, terminals (110, 120, 130, 140) may be depicted as servers, personal computers, and smartphones, but the principles of the present disclosure cannot be limited to this. Embodiments of the present disclosure find application in laptop computers, tablet computers, media players, and/or specialized video conferencing equipment. Network (150) is any number of networks that transmit encoded video data between terminals (110, 120, 130, 140), including, for example, wired and/or wireless networks. The communication network (150) may communicate on circuit-switched and/or packet-switched channels. Representative networks include telecommunications networks, local area networks, wide area networks and/or the Internet. For the purposes of this discussion, the architecture and topology of the network (150) may not be essential to the operation of this disclosure, unless explained herein below.

[39] FIG. 2 illustrates, as an example of application for the disclosed subject matter, the placement of a video encoder and a video decoder in a streaming environment. The disclosed subject matter may be equally applicable to other video-enabled applications including, for example, videoconferencing, digital television, storage of compressed video on digital media including CD, DVD, memory card, etc., and so on. .

[40] The streaming system may include a capture subsystem (213), which may include a video source (201), such as a digital camera, producing, for example, a stream (202) of uncompressed video samples. This stream (202) of samples, depicted with a thick line to emphasize the large amount of data compared to the encoded video bitstreams, can be processed by an encoder (203) connected to the camera (201). The encoder (203) may include hardware, software, or a combination thereof to enable or implement aspects of the disclosed subject matter, as described in more detail below. The encoded video bitstream (204), drawn with a thin line to emphasize the smaller amount of data compared to the sample stream, may be stored on the streaming server (205) for future use. One or more streaming clients (206, 208) can access the streaming server (205) to extract copies (207, 209) of the encoded video bitstream (204). The client (206) may include a video decoder (210) that decodes an incoming copy of the encoded video bitstream (207) and creates an outgoing stream (211) of video samples that can be displayed on a display (212) or other visualization device (not shown) . In some streaming systems, video bitstreams (204, 207, 209) may be encoded according to certain video coding/compression standards. Examples of these standards include ITU-T Rec. H.265. A video coding standard is under development, informally known as Universal Video Coding or VVC. The expanded object can be used in a VVC context.

[41] FIG. 3 may be a functional block diagram of a video decoder (210) according to an embodiment of the present disclosure.

[42] The receiver (310) may receive one or more encoded video sequences to be decoded by the video decoder (210); in the same or another embodiment, one coded video sequence at a time, where the decoding of each coded video sequence is independent of other coded video sequences. An encoded video sequence may be received from a channel (312), which may be a hardware/software connection to a storage device that stores the encoded video data. The receiver (310) may receive encoded video data with other data, such as encoded audio data and/or ancillary data streams, which may be sent to their respective using entities (not shown). The receiver (310) may separate the encoded video sequence from other data. To combat network jitter, a buffer memory (315) can be connected between the receiver (310) and the entropy decoder/parser (320) (hereinafter "parser"). When the receiver (310) receives data from a storage/transfer device with sufficient bandwidth and controllability, or from an isosynchronous network, buffer memory (315) may not be needed or may be small. For use in best quality packet networks such as the Internet, a buffer (315) may be required, which may be relatively large and may preferably be of an adaptive size.

[43] The video decoder (210) may include a parser (320) for recovering the symbols (321) from the entropy coded video sequence. The categories of these symbols include information used to control the operation of the decoder (210) and potentially information to control a visualization device such as a display (212) which is not an integral part of the decoder but can be connected to it as shown. in fig. 2. The control information for the rendering device(s) may be in the form of parameter set fragments of incremental enhancement information (SEI messages) or video usability information (VUI) (not shown). The parser (320) may parse/entropy decode the received encoded video sequence. Encoding of the encoded video sequence may be in accordance with a video coding technology or standard, and may follow principles well known to those skilled in the art, including variable length coding, Huffman coding, arithmetic coding with or without context sensitivity, and so on. The parser (320) may extract from the encoded video sequence a set of subgroup parameters for at least one of the subgroups of pixels in the video decoder based on at least one parameter corresponding to the group. Subgroups may include groups of pictures (GOPs), pictures, tiles, slices, macroblocks, coding units (CUs), blocks, transform units (TUs), prediction units (PUs), and so on. The entropy decoder/parser may also extract information from the encoded video sequence, such as transform coefficients, quantizer parameter values, motion vectors, and so on.

[44] The parser (320) may perform an entropy decoding/parsing operation of the video sequence received from the buffer (315) to create symbols (321).

[45] Symbol recovery (321) may include many different modules depending on the type of encoded video image or parts thereof (such as: external and internal image, external and internal block) and other factors. Which modules are involved and how can be controlled by the subgroup control information parsed from the encoded video sequence by the parser (320). The flow of such subgroup control information between the parser (320) and the plurality of modules is not shown below for clarity.

[46] In addition to the functional blocks already mentioned, the decoder 210 can be conceptually subdivided into a number of functional modules, as described below. In a practical implementation operating under commercial constraints, many of these modules interact closely with each other and can be at least partially integrated into each other. However, for purposes of describing the disclosed subject matter, the conceptual division into functional modules below is appropriate.

[47] The first module is the scaling/inverse transform module (351). The scaling/inverse transform module (351) receives the quantized transform coefficient, as well as control information, including which transform to use, block size, quantization factor, quantization scaling matrices, and so on, in the form of symbol(s) (321) from the parser ( 320). It can output blocks containing sample values that can be entered into the aggregator (355).

[48] In some cases, the output samples of the scaling/inverse transform module (351) may refer to an intra-coded block; that is, to a block that does not use prediction information from previously restored images, but can use prediction information from previously restored portions of the current image. Such prediction information may be provided by the intra prediction module (352). In some cases, the intra-prediction module (352) generates a block of the same size and shape as the reconstructed block using the already reconstructed surrounding information extracted from the current (partially reconstructed) image (358). The aggregator (355), in some cases, adds for each sample the prediction information generated by the intra-prediction module (352) to the output sample information provided by the scaling/inverse transform module (351).

[49] In other cases, the output samples of the scaling/inverse transform module (351) may refer to a block with intercoding and potentially with motion compensation. In such a case, the motion compensation prediction module (353) may access the reference picture memory (357) to retrieve samples used for prediction. After compensating for the movement of the selected samples in accordance with the symbols (321) associated with the block, these samples can be added by the aggregator (355) to the output of the scaler/demap module (in this case, they are called residual samples or residual signal) to generate information about output counts. Reference picture memory addresses from where the motion compensation prediction module selects prediction samples may be driven by motion vectors available to the motion compensation prediction module in the form of symbols (321), which may have X, Y and reference picture components, for example. Motion compensation may also include interpolation of sample values retrieved from reference picture memory when accurate sub-sample motion vectors are used, motion vector prediction mechanisms, and so on.

[50] The output samples of the aggregator (355) may be subjected to various loop filtering methods in the loop filter module (356). The video compression technologies may include in-loop filtering technologies that are controlled by parameters included in the encoded video bitstream and provided to the loop filtering module (356) as symbols (321) from the parser (320), but may also respond to metainformation received during decoding the previous (in the order of decoding) parts of the encoded image or encoded video sequence, as well as responding to previously restored and filtered by loop filtering sample values.

[51] The output of the loop filter module (356) may be a stream of samples that can be output to the renderer (212) and also stored in the reference picture memory (357) for use in future inter-picture prediction.

[52] Certain encoded pictures after full recovery can be used as reference pictures for future prediction. Once the encoded picture has been completely reconstructed and the encoded picture has been identified as a reference picture (eg, by the parser (320)), the current reference picture (358) may become part of the reference picture buffer (357), and fresh current picture memory may be reallocated before the beginning of the reconstruction of the next encoded picture.

[53] Video decoder 320 may perform decoding operations according to a predetermined video compression technology that may be written in a standard such as ITU-T Rec. H.265. The encoded video sequence may conform to the syntax given by the video compression technology or standard used, in the sense that it conforms to the syntax of the video compression technology or standard as specified in the video compression technology document or standard, and in particular their profile document. It may also be necessary for compliance that the complexity of the encoded video sequence be within limits defined by the level of technology or video compression standard. In some cases, levels limit the maximum image size, the maximum frame rate, the maximum recovery sampling rate (measured in megasamples per second, for example), the maximum reference image size, and so on. The limits set by the layers may, in some cases, be further constrained by hypothetical reference decoder (HRD) specifications and metadata for managing the HRD buffer transmitted in the encoded video sequence.

[54] In an embodiment, the receiver (310) may receive additional (redundant) data with encoded video. Additional data may be included as part of the encoded video sequence(s). The additional data may be used by the video decoder (320) to correctly decode the data and/or to more accurately reconstruct the original video data. The additional data may be in the form of, for example, temporal, spatial or signal-to-noise ratio (SNR) enhancement layers, redundant slices, redundant images, forward error correction codes, and so on.

[55] FIG. 4 may be a functional block diagram of a video encoder (203) according to an embodiment of the present disclosure.

[56] The encoder (203) may receive video samples from a video source (201) (which is not part of the encoder) that may capture video image(s) for encoding by the encoder (203).

[57] The video source (201) may provide the source video sequence for encoding by the encoder (203) in the form of a digital stream of video samples, which may have any suitable bit depth (eg: 8 bit, 10 bit, 12 bit, ...), any color space (eg, BT.601 Y CrCB, RGB, ...) and any suitable sample structure (eg, Y CrCb 4:2:0, Y CrCb 4:4:4). In a media serving system, the video source (201) may be a storage device storing pre-prepared video. In a videoconferencing system, the video source (203) may be a camera that captures local image information as a video sequence. The video data may be provided as a plurality of individual images that, when viewed sequentially, convey motion. The images themselves can be organized as a spatial array of pixels, in which each pixel can contain one or more samples depending on the sample structure used, color space, and so on. One skilled in the art can easily understand the relationship between pixels and samples. The description below is based on readings.

[58] According to an embodiment, the video encoder (203) may encode and compress images of the source video sequence into the encoded video sequence (443) in real time or with any other time constraints as required by the application. Providing an appropriate coding rate is one of the functions of the controller (450). The controller controls other functional modules, as described below, and is functionally associated with these modules. The connection is not shown for clarity. The parameters set by the controller may include parameters related to speed control (picture skip, quantizer, speed-distortion optimization methods lambda value, ...), image size, group of pictures (GOP) layout, maximum motion vector search range, and so on. . A person skilled in the art can easily determine other functions of the controller (450) as they may relate to a video encoder (203) optimized for a particular system design.

[59] Some video encoders operate in what one of ordinary skill in the art would readily recognize as a "coding loop". As a simplified description, an encoding loop may consist of an encoder coding part (430) (hereinafter "source encoder") (responsible for creating symbols based on the input picture to be encoded and the reference picture(s)), and a (local) decoder (433) built into the encoder (203) that decompresses the symbols to create sample data that the (remote) decoder can also create (because any compression between the symbols and the encoded video bitstream is lossless in the video compression technologies discussed in the disclosed subject matter). ). This reconstructed sample stream is entered into the reference picture memory (434). Because decoding a stream of symbols results in bit-accurate results, regardless of the location of the decoder (local or remote), the contents of the reference picture buffer are also bit-accurate between the local encoder and the remote encoder. In other words, the prediction portion of the encoder "sees" as reference picture samples exactly the same sample values that the decoder would "see" using prediction during decoding. This fundamental principle of reference picture synchronism (and the resulting drift if synchronism cannot be maintained due to, for example, channel errors) is well known to those skilled in the art.

[60] The operation of the "local" decoder (433) may be the same as that of the "remote" decoder (210), which has already been described in detail above with reference to FIG. 3. Briefly referring also to FIG. 3, however, since the symbols are available and encoding/decoding of the symbols into the encoded video sequence by the entropy encoder (445) and parser (320) can be lossless, the entropy decoding parts of the decoder (210), including the channel (312), the receiver (310), buffer (315) and parser (320) cannot be fully implemented in the local decoder (433).

[61] At this point, it can be observed that any decoding technology other than parsing/entropy decoding that is present in a decoder must also necessarily be present in substantially identical functional form in the corresponding encoder. For this reason, the disclosed subject matter focuses on the operation of the decoder. The description of encoding technologies can be abbreviated as they are the inverse of fully described decoding technologies. Only in some areas a more detailed description is required, which is given below.

[62] As part of its operation, the source encoder (430) may perform motion-compensated predictive encoding that predictively encodes the input frame with reference to one or more previously encoded frames from the video sequence, which have been designated "reference frames". Thus, the coding engine (432) encodes the differences between the pixel blocks of the input frame and the pixel blocks of the reference frame(s) that can be selected as the prediction reference(s) for the input frame.

[63] The local video decoder (433) may decode the encoded video data of the frames, which may be designated as reference frames, based on the symbols generated by the source encoder (430). The operations of the encoding engine (432) may preferably be lossy processes. When the encoded video data can be decoded in a video decoder (not shown in FIG. 4), the reconstructed video sequence can typically be a copy of the original video sequence with some errors. The local video decoder (433) replicates the decoding processes that may be performed by the video decoder on the reference frames and may cause the recovered reference frames to be stored in the reference picture cache (434). Thus, the encoder (203) can locally store copies of the reconstructed reference frames that share content as the reconstructed reference frames to be received by the far-end video decoder (in the absence of transmission errors).

[64] The predictor (435) may perform predictive searches for the encoding engine (432). That is, for a new picture to be encoded, the predictor (435) may search the reference picture memory (434) for sample data (as reference pixel block candidates) or certain metadata such as reference picture motion vectors, block shapes, and so on. further, which can serve as a suitable prediction reference for new images. The predictor (435) may operate on a block-by-pixel basis to find appropriate prediction references. In some cases, as determined by the search results obtained by the predictor (435), the input image may have prediction references taken from a plurality of reference pictures stored in the reference picture memory (434).

[65] The controller (450) may control the encoding operations of the video encoder (430), including, for example, setting parameters and subgroup parameters used to encode video data.

[66] The output signals of all the above functional modules can be entropy encoded in an entropy encoder (445). The entropy encoder translates symbols generated by various functional modules into an encoded video sequence by lossless symbol compression according to techniques known to those skilled in the art, such as Huffman coding, variable length coding, arithmetic coding, and so on.

[67] The transmitter (440) may buffer the encoded video sequence(s) generated by the entropy encoder (445) to prepare it for transmission over a communication channel (460), which may be a hardware/software connection to a storage device that will store the encoded video data. . The transmitter (440) may merge the encoded video data from the video encoder (430) with other data to be transmitted, such as encoded audio data and/or ancillary data streams (sources not shown).

[68] The controller (450) may control the operation of the encoder (203). During encoding, the controller (450) may assign to each encoded picture a certain type of encoded picture, which may affect the encoding methods that can be applied to the corresponding picture. For example, images can often be classified as one of the following frame types.

[69] An intra-picture (I-picture) may be one that can be encoded and decoded without using any other frame in the sequence as a prediction source. Some video codecs allow various types of internal images, including, for example, images with independent decoder update. The person skilled in the art will be aware of these variants of I-images and their respective uses and features.

[70] A predictive picture (P-picture) may be one that can be encoded and decoded using intra-prediction or inter-prediction using at most one motion vector and a reference index to predict sample values of each block.

[71] A bidirectional predictive picture (B-picture) may be one that can be encoded and decoded using intra-prediction or inter-prediction using at most two motion vectors and reference indices to predict sample values of each block. Similarly, multi-prediction images may use more than two reference images and associated metadata to reconstruct a single block.

[72] Source images can typically be spatially divided into multiple blocks of samples (eg, blocks of 4x4, 8x8, 4x8, or 16x16 samples each) and encoded on a block-by-block basis. The blocks may be predictively encoded with reference to other (already encoded) blocks, as determined by the coding assignment applied to the corresponding block images. For example, blocks of I-pictures may be predictively encoded or they may be predictively encoded with reference to already encoded blocks of the same picture (spatial prediction or intra prediction). P-picture pixel blocks may be encoded without prediction, by spatial prediction, or by temporal prediction with reference to one previously encoded reference picture. Blocks of B-pictures may be encoded without prediction, by spatial prediction, or by temporal prediction with reference to one or two previously encoded reference pictures.

[73] The video encoder (203) may perform encoding operations in accordance with a predetermined video coding technology or standard, such as ITU-T Rec. H.265. In operation, the video encoder (203) may perform various compression operations, including predictive coding operations that exploit temporal and spatial redundancy in the input video sequence. The encoded video data may therefore follow the syntax given by the video coding technology or standard used.

[74] In an embodiment, transmitter (440) may transmit additional data with encoded video. Video encoder (430) may include such data as part of an encoded video sequence. The additional data may comprise temporal/spatial/SNR enhancement layers, other forms of redundant data such as redundant images and slices, incremental enhancement information (SEI) messages, video usability information (VUI) parameter set fragments, and so on.

[75] Before a more detailed description of certain aspects of the disclosed subject matter, it is necessary to introduce a few terms that will be referred to in the remainder of this description.

[76] A sub-image further refers, in some cases, to a rectangular arrangement of samples, blocks, macroblocks, coding units, or the like, which are semantically grouped and which can be independently encoded with a changed resolution. One or more sub-images may be used for an image. One or more encoded sub-pictures may form an encoded picture. One or more sub-images may be assembled into an image, and one or more sub-images may be extracted from the image. In certain environments, one or more encoded sub-images may be collected in the compressed region without recoding to the sample level in the encoded image, and in the same or some other cases, one or more encoded sub-images may be extracted from the encoded image in the compressed region.

[77] Hereinafter, reference picture resampling (RPR) or adaptive resolution change (ARC) refers to mechanisms that allow changing the resolution of an image or sub-picture in a coded video sequence, for example, by reference picture resampling. Hereinafter, RPR/ARC parameters refer to control information necessary to perform adaptive resolution change, which may include, for example, filter parameters, scaling factors, output and/or reference picture resolutions, various control flags, and so on.

[78] The above description focuses on encoding and decoding a single semantically independent encoded video image. Before describing the consequences of encoding/decoding multiple sub-pictures with independent RPR/ARC parameters and their implied additional complexity, RPR/ARC parameter transmission options must be described.

[79] FIG. Figure 5 shows several new options for passing RPR/ARC parameters. As noted for each of the options, they have certain advantages and certain disadvantages in terms of coding efficiency, complexity and architecture. A video coding standard or technology may choose one or more of these or prior art options for transmitting the RPR/ARC parameters. The options may not be mutually exclusive and may possibly be interchangeable depending on the needs of the application, the standards used, or the choice of encoder.

[80] RPR/ARC parameter classes may include:

- upsampling/downsampling coefficients, separate or combined in the X and Y dimensions,

- upsampling/downsampling ratios with the addition of a temporal dimension, indicating an increase/decrease in size at a constant rate for a given number of images,

- either of the above two options may involve encoding one or more supposedly short syntax elements that may point to a table containing the coefficient(s),

- the resolution in X or Y dimensions, in units of samples, blocks, macroblocks, CU or any other suitable granularity, of the input image, output image, reference image, coded image, combined or single (if there is more than one resolution (such as for example , one for the input image, one for the reference image), then in some cases one set of values can be derived from another set of values. This can be passed, for example, using flags. See below for a more detailed example,

- "strain" coordinates like those used in H.263 Annex P, again with the appropriate granularity as described above. (Annex P H.263 defines one efficient way to encode such warp coordinates, but other potentially more efficient ways may also be developed. , where the length of the binary codeword can be, for example, obtained from the maximum image size, possibly multiplied by a certain factor and offset by a certain value to account for "warping" beyond the bounds of the maximum image size), and/or

- upsampling or downsampling filter parameters (in the simplest case, there can be only one upsampling and/or downsampling filter. However, in some cases it may be desirable to provide more flexibility in the design of the filter, and this may require passing filter parameters. Such parameters may be selected by an index into a list of possible filter designs, the filter may be fully specified (e.g., by a list of filter coefficients using appropriate entropy coding techniques), the filter may be implicitly selected by appropriate upsampling/downsampling relationships that, in are in turn transmitted according to any of the mechanisms mentioned above, and so on).

[81] The following description assumes encoding a finite set of upsampling/downsampling coefficients (the same coefficient to be used in the X and Y dimensions) indicated by a codeword. This codeword may advantageously be encoded with a variable length, for example, using the Exponential Golomb code common to certain syntax elements in video coding specifications such as H.264 and H.265. One suitable mapping of values to upsampling/downsampling coefficients may, for example, correspond to the following Table 1.

[82] Many similar mappings can be developed according to the needs of the application and the capabilities of the upsampling and downsampling mechanisms available in the video compression technology or standard. The table can be expanded to more values. Values may also be represented by entropy encoding mechanisms other than Exponential Golomb codes, such as using binary encoding. This may have certain advantages when the oversampling factors were of interest outside of the video processing engines themselves (primarily the encoder and decoder), for example via MANE. It should be noted that for the (presumably) most common case where no resolution change is required, exponential Golomb code, which is short, can be chosen; there is only one bit in the table above. This may have an advantage in coding efficiency over using binary codes for the most common case.

[83] The number of entries in the table, as well as their semantics, can be completely or partially customizable. For example, the basic table structure may be conveyed in a "high" parameter set, such as a sequence or a decoder parameter set. Alternatively, or in addition, one or more such tables may be defined in a video coding technology or standard and may be selected, for example, by a decoder or sequence parameter set.

[84] The following describes how the upsampling/downsampling ratio (ARC information) encoded as described above can be included in a video coding technology or a standard syntax. Similar considerations may apply to one or more codewords driving the upsampling/downsampling filters. The following is a discussion of when relatively large amounts of data are required for a filter or other data structures.

[85] As shown in the example of FIG. 5A, illustration (500A) shows that H.263 Annex P includes ARC information (502) in the form of four warp coordinates in the picture header (501), specifically in the H.263 PLUSPTYPE header extension (503). This may be a reasonable design choice when a) there is an image header available and b) frequent changes to the ARC information are expected. However, the overhead when using H.263 style transmission can be quite high, and the scaling factors may not be related to the image borders, since the image header may be temporary. In addition, as shown in the example of FIG. 5B, illustration (500B) shows that JVET-M0135 includes PPS information (504), ARC reference information (505), SPS information (507), and target permission table information (506).

[86] According to exemplary embodiments, FIG. 5C illustrates an example (500C) showing tile group header information (508) and ARC information (509); fig. 5B illustrates an example (500D) showing tile group header information (514), ARC reference information (513), SPS information (516), and ARC information (515), and FIG. 5E illustrates an example (500E) in which adaptation parameter set(s) (APS) information (511) and ARC information (512) are shown.

[87] FIG. 6 shows an example (600) of a table that uses adaptive resolution, in this example the output resolution is encoded in units of samples (613). Position number 613 refers to both output_pic_width_in_luma_samples and output_pic_height_in_luma_samples, which together can determine the resolution of the output image. Elsewhere in a video coding technology or standard, certain restrictions may be defined for any value. For example, the level definition may limit the number of total output samples that can be the product of the values of these two syntax elements. Also, certain video coding technologies or standards, or external technologies or standards such as, for example, system standards, may restrict the numbering range (for example, one or both dimensions must be divisible by a power of 2) or width-to-height ratio (for example, width and height must be in a ratio such as 4:3 or 16:9). Such restrictions may be introduced to facilitate hardware implementations or for other reasons, as will be appreciated by one of ordinary skill in the art in light of the present disclosure.

[88] In some applications, it may be desirable for the encoder to instruct the decoder to use a specific reference picture size instead of implicitly assuming that this size is the size of the output picture. In this example, the syntax element reference_pic_size_present_flag (614) conveys the conditional presence of the dimensions (615) of the reference picture (again, the figure refers to both width and height).

[89] Some video coding technologies or standards, such as VP9, support spatial scalability by implementing certain forms of reference picture resampling (transmitted quite differently than in the disclosed subject matter) in combination with temporal scalability to provide spatial scalability. In particular, some reference pictures may be upsampled using ARC-style techniques to higher resolution to form the basis of the spatial enhancement layer. These upsampled images can be enhanced using normal high resolution prediction engines to add detail.

[90] The disclosed subject matter can be and is used in such an environment according to the embodiments. In some cases, in the same or another embodiment, a value in the NAL unit header, such as a temporal identifier field, may be used to indicate not only the temporal but also the spatial layer. This offers certain advantages for certain system configurations; for example, an existing Selected Forwarding Units (SFU) created and optimized for selected temporal slices forwarded based on the value of the NAL unit header's temporal identifier can be used without modification for scalable environments. In order to make this possible, there may be a requirement for a mapping between the encoded picture size and the temporal layer indicated by the temporal identifier field in the NAL unit header.

[91] In embodiments, cross-layer dependency information may be conveyed in VPS (or DPS, SPS, or SEI messages). The interlayer dependency information may be used to identify which layer is being used as a reference layer for decoding the current layer. A decoded forward dependent layer picture picA with nuh_layer_id equal to m can be used as a reference picture for picture picB with nuh_layer_id equal to n when n is greater than m and two pictures picA and picB belong to the same access unit.

[92] In the same or other embodiments, an interlayer reference picture list (ILRP) may be explicitly conveyed using an interlayer prediction reference picture list (IPRP) in the slice header (or parameter set). Both ILRP lists and IPRP lists can be used to construct forward and backward prediction reference picture lists.

[93] In the same or other embodiments, the implementation of the syntax elements in the VPS (or other set of parameters) may indicate whether each layer is dependent or independent. Referring to example (700) of FIG. 7, the syntax element vps_max_layers_minus1 (703) plus 1 may indicate the maximum number of layers allowed in one or more, potentially all, VPS-related CVSs (701). vps_all_independent_layers_flag (704) equal to 1 may indicate that all layers in CVS are encoded independently, ie without using interlayer prediction. vps_all_independent_layers_flag (704) equal to 0 may indicate that one or more layers in CVS may use interlayer prediction. If not present, the value of vps_all_independent_layers_flag may be inferred to be 1. When vps_all_independent_layers_flag is equal to 1, the value of vps_independent_layer_flag[i] (706) may be inferred to be 1. When vps_all_independent_layers_flag is equal to 0, the value of vps_independent_layer_flag[0] is assumed to be 1.

[94] Referring to FIG. 7, vps_independent_layer_flag [i] (706) equal to 1 may indicate that the layer at index i does not use interlayer prediction. vps_independent_layer_flag [i] equal to 0 may indicate that the layer with index i can use interlayer prediction, and vps_layer_dependency_flag [i] is present in the VPS. vps_direct_dependency_flag [i] [j] (707) equal to 0 may indicate that layer index j is not a direct reference layer for layer index i. vps_direct_dependency_flag [i] [j] equal to 1 may indicate that layer index j is a direct reference layer for layer index i. When vps_direct_dependency_flag [i] [j] is not present for i and j in the range 0 to vps_max_layers_minus1 inclusive, it may be output as 0.

[95] The variable DirectDependentLayerIdx[i][j], indicating the jth direct dependent layer of the i-th layer, and the variable NumDependentLayers[i], indicating the number of dependent layers of the i-th layer, are output as follows:

[96] In the same or another embodiment, with reference to FIG. 7, when vps_max_layers_minus1 is greater than zero and vps_all_independent_layers_flag is zero, vps_output_layers_mode and vps_output_layer_flags [i] may be transmitted. vps_output_layers_mode (708) equal to 0 may indicate that only the highest layer is output. vps_output_layer_mode equal to 1 indicates that all layers can be output. vps_output_layer_mode equal to 2 may indicate that the output layers are layers with vps_output_layer_flag [i] (709) equal to 1. vps_output_layers_mode must be between 0 and 2 inclusive. The value 3 vps_output_layer_mode can be reserved for future use. If absent, the vps_output_layers_mode value may be output to 1. vps_output_layer_flag[i] equal to 1 may indicate that the i-th layer is output. vps_output_layer_flag [i] equal to 0 may indicate that the i-th layer is not output. The OutputLayerFlag [i] list, for which a value of 1 can indicate that the i-th layer is being output, and a value of 0 indicates that the i-th layer is not being output, is output as follows:

[97] In the same or another embodiment, the output of the current image can be defined as follows:

- If PictureOutputFlag is 1 and DpbOutputTime[n] is CpbRemovalTime[n], the current image is output.

- Otherwise, if PictureOutputFlag is 0, the current image is not output, but will be stored in the DPB as specified in paragraph.

- Otherwise (PictureOutputFlag is 1 and DpbOutputTime[n] is greater than CpbRemovalTime[n]), current image is output later and will be stored in DPB (as specified in clause) and output at DpbOutputTime[n] if not specified that it is not output by decoding or by outputting no_output_of_prior_pics_flag equal to 1 at a time prior to DpbOutputTime[n].

On output, the image is cropped using the appropriate crop window specified in the PPS for the image.

[98] In the same or different embodiment, the PictureOutputFlag can be set as follows:

- If one of the following conditions is true, PictureOutputFlag is set to 0:

- the current image is a RASL image and the NoIncorrectPicOutputFlag value of the associated IRAP image is 1.

- gdr_enabled_flag is 1 and the current image is a GDR image with NoIncorrectPicOutputFlag set to 1.

- gdr_enabled_flag is 1, the current picture is associated with a GDR picture with NoIncorrectPicOutputFlag equal to 1, and the PicOrderCntVal of the current picture is less than the RpPicOrderCntVal of the associated GDR picture.

- vps_output_layer_mode is 0 or 2 and OutputLayerFlag [GeneralLayerIdx [nuh_layer_id]] is 0.

- Otherwise, PictureOutputFlag is set to pic_output_flag.

[99] In the same or another embodiment, alternatively, the PictureOutputFlag may be set as follows.

- If one of the following conditions is true, PictureOutputFlag is set to 0:

- The current image is a RASL image and the NoIncorrectPicOutputFlag value of the associated IRAP image is 1.

- gdr_enabled_flag is 1 and the current image is a GDR image with NoIncorrectPicOutputFlag set to 1.

- gdr_enabled_flag is 1, the current picture is associated with a GDR picture with NoIncorrectPicOutputFlag equal to 1, and the PicOrderCntVal of the current picture is less than the RpPicOrderCntVal of the associated GDR picture.

- vps_output_layer_mode is 0 and the current access unit contains an image whose PictureOutputFlag is 1, nuh_layer_id nuhLid is greater than the current image, and belongs to the output layer (i.e. OutputLayerFlag [GeneralLayerIdx [nuhLid]] is 1).

- vps_output_layer_mode is 2 and OutputLayerFlag [GeneralLayerldx [nuh_layer_id]] is 0.

- Otherwise, PictureOutputFlag is set to pic_output_flag.

[100] In the same or another embodiment, a flag in the VPS (or other set of parameters) may indicate whether or not ILRPs are transmitted for the current slice (or picture). For example, referring to example (800) of FIG. 8, inter_layer_ref_pics_present_fiag equal to 0 may indicate that no ILRP is used to interpredict any encoded picture in CVS. inter_layer_ref_pics_flag equal to 1 may indicate that ILRPs may be used to interpredict one or more encoded pictures in CVS.

[101] In the same or other embodiments, an interlayer reference picture list (ILRP) for an image in the k-th layer may or may not be transmitted when the k-th layer is a dependent layer. However, the ILRP list for a picture in the kth layer should not be transmitted, and no ILRP should be included in the reference picture list when the kth layer is an independent layer.

[102] inter_layer_ref_pics_present_flag may be set to 0 when sps_video_parameter_set_id is 0, when nuh_layer_id is 0, or when vps_independent_layer_flag [GeneralLayerIdx [nuh_layer_id]] is 1.

[103] In the same or other embodiments, with reference to example (900) of FIG. 9, a set of syntax elements that explicitly specify an ILRP list may be passed in an SPS, PPS, APS, or slice header. The ILRP list may be used to create a reference picture list of the current picture.

[104] In the same or other embodiments, the ILRP list may be used to identify an active or inactive reference picture in a decoded picture buffer (DPB). An active reference picture may be used as a reference picture for decoding the current picture, while an inactive reference picture may not be used for decoding the current picture but may be used for decoding a subsequent picture in decoding order.

[105] In the same or another embodiment, the ILRP list can be used to identify which reference picture can be stored in the DPB or can be output and removed from the DPB. This information can be used to operate the decoder based on the hypothetical reference decoder (HRD) model and parameters.

[106] In the same or a different embodiment, the ilrp_idc [listIdx] [rplsIdx] [i] syntax element may be carried in a VPS, SPS, PPS, APS, or slice header. The ilrp_idc [listIdx] [rplsIdx] [i] syntax element specifies the index, for a list of directly dependent layers, of the ILRP i-th entry in the ref_pic_list_struct(listIdx, rplsIdx) syntax structure for a list of directly dependent layers. The value of ilrp_idc [listIdx] [rplsIdx] [i] must be between 0 and GeneralLayerIdx [nuh_layer_id] - 1 inclusive.

[107] In the same embodiment, the ilrp_idc [listIdx] [rplsIdx] [i] syntax element may be an index indicating the ILRP image among the directly dependent layers that are identified by the vps_direct_dependency_flag [i] [j] passed to the VPS. In this case, the value of ilrp_idc[listIdx][rplsIdx][i] must be in the range 0 to NumDependentLayers[GeneralLayerldx[nuh_layer_id]] - 1 inclusive.

[108] In the same embodiment, when the nuh_layer_id of the current layer is equal to k, it may be bit-efficient to transmit an index indicating ILRP among directly dependent layers, as compared to transmitting an index indicating ILRP among all layers with nuh_layer_id less than k.

[109] In the same or different embodiment, still referring to FIG. 9, reference picture lists RefPicList[0] and RefPicList[1] can be constructed as follows:

[110] The techniques for transmitting adaptive resolution parameters described above may be implemented in computer software using computer-readable instructions and physically stored on one or more computer-readable media. For example, in FIG. 10 shows a computer system (1000) suitable for implementing certain embodiments of the disclosed subject matter.

[111] Computer software may be coded using any suitable machine code or computer language, which may be the object of assembly, compilation, linking, or similar mechanisms to produce code containing instructions that can be executed directly or through interpretation, execution of microcode, and and the like, computer central processing units (CPUs), graphics processing units (GPUs), and the like.

[112] The instructions may be executed on various types of computers or components thereof, including, for example, personal computers, tablet computers, servers, smartphones, gaming devices, IoT devices, and the like.

[113] The components shown in FIG. 10 for computer system (1000) are exemplary in nature and are not intended to suggest any limitation as to the scope of use or functionality of computer software implementing embodiments of the present disclosure. The configuration of the components is also not to be interpreted as having any dependency or requirement relating to any one or combination of the components illustrated in the exemplary embodiment of the computer system (1000).

[114] The computer system (1000) may include certain human-machine interface input devices. Such a human-machine interface input device may respond to input by one or more human users through, for example, tactile input (e.g., keystrokes, swipes, movement of a control glove), audio input (e.g., voice, handclaps), visual input (for example: gestures), olfactory input (not shown). HMI devices can also be used to capture certain media not necessarily directly related to conscious human input, such as sound (e.g. speech, music, ambient sound), images (e.g. scanned images, photographic images taken from a camera for still images), video (eg 2D video, 3D video including stereoscopic video).

[115] Human interface input devices may include one or more of (only one of each depicted): keyboard (1001), mouse (1002), trackpad (1003), touch screen (1010), joystick ( 1005), microphone (1006), scanner (1007), camera (1008).

[116] The computer system (1000) may also include certain human-machine interface output devices. Such human interface output devices can stimulate the senses of one or more human users through, for example, tactile output, sound, light, and smell/taste. Such HMI output devices may include tactile output devices (e.g., haptic feedback from a touch screen (1010) or joystick (1005), but there may also be tactile feedback devices that do not serve as input devices) , audio output devices (for example: speakers (1009), headphones (not shown)), image output devices (for example, screens (1010), including CRT screens, LCD screens, plasma screens, OLED screens, each of which has or no touchscreen input capability, each with or without haptic feedback capability - some of which may be capable of producing 2D visual output or more than 3D output by means such as stereographic output; virtual reality goggles (not shown ), holographic displays and smoke tanks (not shown)) and printers (not shown).

[117] The computer system (1000) may also include human accessible storage devices and associated media such as optical media including CD/DVD ROM/RW (1020) with CD/DVD or similar media (1021), flash drive (1022), removable hard drive or solid state drive (1023), previously developed magnetic media such as tape and floppy disk (not shown), specialized ROM/ASIC/PLD based devices such as dongles (not shown) and so on.

[118] Those skilled in the art should also understand that the term "computer-readable medium" as used in connection with the subject matter disclosed herein does not encompass transmission media, carrier waves, or other time signals.

[119] The computer system (1000) may also include an interface to one or more communication networks. Networks can be, for example, wireless, wired, optical. In addition, networks can be local, wide area, metropolitan, automotive, industrial, real-time, latency tolerant, and so on. Example networks include local area networks such as Ethernet, wireless LANs, cellular networks including GSM, 3G, 4G, 5G, LTE, etc., wired television or wireless digital wide area networks including cable television, satellite television and terrestrial TV broadcasting, automotive and industrial equipment, including CAN bus, etc. Some networks typically require external network interface adapters that are connected to certain general purpose data ports or peripheral buses (1049) (for example, computer system USB ports (1000)); others are typically integrated into the computer system core (1000) by being attached to a system bus as described below (eg, an Ethernet interface to a PC computer system or a cellular network interface to a smartphone computer system). Using any of these networks, the computer system (1000) can communicate with other entities. Such communication can be unidirectional, receive-only (for example, broadcast television), unidirectional, send-only (for example, CAN bus to certain CAN-bus devices), or bidirectional, for example, to other computer systems using a local or wide area digital network. . Each of these networks and network interfaces may use specific protocols and protocol stacks as described above.

[120] The above human-machine interface devices, human-accessible storage devices, and network interfaces may be attached to the core (1040) of the computer system (1000).

[121] The core (1040) may include one or more central processing units (CPUs) (1041), graphics processing units (GPUs) (1042), dedicated field programmable gate array processors (FPGAs) (1043), hardware accelerators (1044) for certain tasks, etc. These devices, along with Read Only Memory (ROM) (1045), Random Access Memory (1046), high capacity internal storage such as internal non-user hard drives, solid state drives (SSDs), and the like. (1047) can be connected via the system bus (1048). In some computer systems, the system bus (1048) may be available as one or more physical connectors to allow expansion with additional CPUs, GPUs, or the like. Peripherals can be connected either directly to the system bus (1048) of the kernel, or via a peripheral bus (1049). Peripheral bus architecture includes PCI, USB, etc.

[122] The CPU (1041), GPU (1042), FPGA (1043), and accelerators (1044) may execute certain instructions, which in combination may constitute the aforementioned computer code. This computer code may be stored in ROM (1045) or RAM (1046). Transient data may also be stored in RAM (1046), while persistent data may be stored in, for example, internal mass storage (1047). Fast storage and retrieval to any of the storage devices can be achieved through the use of cache memory, which can be closely associated with one or more CPU (1041), GPU (1042), mass storage (1047), ROM (1045), RAM (1046), etc.

[123] The computer-readable medium may contain computer code for performing various computer-implemented operations. The media and computer code may be specially designed and constructed for the purposes of this disclosure, or they may be well known and available to those skilled in the art of computer software.

[124] By way of example, and not limitation, a computer system having an architecture (1000), and in particular a core (1040), may provide functionality as a result of having processor(s) (including CPUs, GPUs, FPGAs, accelerators, etc.). .p.) that executes software embodied on one or more tangible, machine-readable media. Such computer-readable media may be media associated with user accessible mass storage as described above, as well as certain kernel storage (1040) that is non-transitory in nature, such as internal kernel mass storage (1047) or ROM (1045). Software implementing various embodiments of the present disclosure may be stored on such devices and executed by the kernel (1040). The computer-readable medium may include one or more memory devices or microchips, as appropriate. The software may cause the core (1040), and in particular the processors therein (including the CPU, GPU, FPGA, etc.) to execute certain processes or certain parts of the specific processes described herein, including the definition of data structures stored in RAM (1046) and changing such data structures in accordance with the processes defined by the software. In addition or alternatively, a computer system may provide functionality as a result of logic embedded in or otherwise embodied in hardware circuitry (e.g., an accelerator (1044)) that may operate in place of or in conjunction with software to perform certain processes or individual parts of the specific processes described in this document. The link to the software may include logic and vice versa where applicable. A reference to a computer-readable medium may include circuitry (eg, an integrated circuit (IC)) storing software to execute, circuitry embodying logic to execute, or both, where applicable. The present disclosure includes any suitable combination of hardware and software.

[125] Although this disclosure describes several exemplary embodiments, there are variations, permutations, and various replacement equivalents that fall within the scope of the disclosure. Thus, it will be appreciated that those skilled in the art will be able to develop numerous systems and methods that, although not explicitly shown or described herein, embody the principles of the disclosure and thus fall within its spirit and scope.

Claims (34)

1. A method for video decoding a scalable bit stream, performed by at least one processor, comprising: parsing at least one video parameter set (VPS) comprising at least one syntax element indicating whether at least one layer in the scalable bitstream is one of a dependent scalable bitstream layer and an independent scalable bitstream layer; - determining the number of dependent layers, including the dependent layer, of the scalable bitstream based on a plurality of flags included in the VPS; - decoding the image in the dependent layer by parsing and interpreting the list of interlayer reference images (ILRP); And - decoding an image in the independent layer and another image in the dependent layer in each case without parsing and interpreting the ILRP list. 2. The method of claim 1, wherein decoding an image in an independent layer comprises parsing and interpreting a list of reference images that does not include any decoded image of another layer. 3. The method of claim 1, wherein the list of interlayer reference pictures includes a decoded picture of another layer. 4. The method of claim 1, wherein parsing the at least one VPS further comprises determining if the other syntax element specifies the maximum number of layers. 5. The method of claim 1, wherein parsing the at least one VPS further comprises determining if the VPS contains a flag indicating whether another layer in the scalable bitstream is a reference layer for the at least one layer. 6. The method of claim 5, wherein parsing at least one VPS further comprises determining if the flag indicates another layer as a reference layer for at least one layer by specifying an index of the other layer and an index of at least one layer, wherein parsing at least one VPS further comprises determining if the VPS contains another syntax element indicating a value less than a certain number of dependent layers. 7. The method of claim 5, wherein parsing the at least one VPS further comprises determining if the flag indicates that the other layer is not a reference layer for at least one layer by specifying an index of the other layer and an index of at least one layer , wherein parsing at least one VPS further comprises determining whether the VPS contains another syntax element indicating a value less than a certain number of dependent layers. 8. The method of claim 1, wherein parsing at least one VPS further comprises determining if the VPS contains a flag indicating whether a plurality of layers, including at least one layer, is to be decoded by interpreting the ILRP list. 9. The method of claim 1, wherein parsing at least one VPS further comprises determining if the VPS contains a flag indicating whether a plurality of layers, including at least one layer, needs to be decoded without interpreting the ILRP list. 10. The method of claim 1, wherein the ILRP is transmitted using an Interlayer Prediction (IPRP) Reference Picture List at the VPS. 11. A device for video decoding of a scalable bit stream, comprising: - at least one memory configured to store computer program code; - at least one processor configured to access the computer program code and operate in accordance with the instructions of the computer program code, the computer program code including: - parsing code configured to cause at least one processor to parse at least one video parameter set (VPS) containing at least one syntax element indicating whether at least one layer in the scalable bitstream is one of the dependent layer a scalable bitstream and an independent scalable bitstream layer; determining code configured to cause at least one processor to determine the number of dependent layers, including the dependent layer, of the scalable bitstream based on a plurality of flags included in the VPS; a first decoding code configured to cause at least one processor to decode an image in a dependent layer by parsing and interpreting an Interlayer Reference Picture List (ILRP); And - a second decoding code configured to cause at least one processor to decode an image in the independent layer and another image in the dependent layer in each case without parsing and interpreting the ILRP list. 12. The apparatus of claim 11, wherein the second decoding code is further configured to cause at least one processor to decode an image in an independent layer by parsing and interpreting a list of reference pictures that does not include any decoded image of another layer. 13. The apparatus of claim 11, wherein the list of interlayer reference pictures includes a decoded picture of another layer. 14. The apparatus of claim 11, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining if another syntax element specifies a maximum number of layers. 15. The apparatus of claim 11, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether the VPS contains a flag indicating whether another layer in the scalable bitstream is a reference layer for at least one layer. 16. The apparatus of claim 15, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining if a flag indicates another layer as a reference layer for at least one layer by specifying an index another layer and an index of at least one layer, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining if the VPS contains another syntax element indicating a value less than a certain number of dependent layers. 17. The apparatus of claim 15, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether a flag indicates another layer as not being a reference layer for at least one layer by setting an index of another layer and an index of at least one layer, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining if the VPS contains another syntax element indicating a value less than a certain number of dependent layers . 18. The apparatus of claim 11, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether the VPS contains a flag indicating whether a plurality of layers, including at least one layer, needs to be decoded. , by interpreting the ILRP list. 19. The apparatus of claim 11, wherein the parsing code is further configured to cause at least one processor to parse at least one VPS by determining whether the VPS contains a flag indicating whether a plurality of layers, including at least one layer, needs to be decoded. , without interpreting the ILRP list. 20. A non-transitory computer-readable medium storing a program configured to cause a computer to: parsing at least one video parameter set (VPS) containing at least one syntax element indicating whether at least one layer in the scalable bitstream is one of a dependent scalable bitstream layer and an independent scalable bitstream layer; - determine the number of dependent layers, including the dependent layer, scalable bitstream based on the set of flags included in the VPS; - decode the image in the dependent layer by parsing and interpreting the list of interlayer reference images (ILRP); And - decode an image in the independent layer and another image in the dependent layer in each case without parsing and interpreting the ILRP list.

Images